xref: /openbmc/linux/fs/nfs/nfs4session.h (revision d9fd5a71)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * fs/nfs/nfs4session.h
4  *
5  * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
6  *
7  */
8 #ifndef __LINUX_FS_NFS_NFS4SESSION_H
9 #define __LINUX_FS_NFS_NFS4SESSION_H
10 
11 /* maximum number of slots to use */
12 #define NFS4_DEF_SLOT_TABLE_SIZE (64U)
13 #define NFS4_DEF_CB_SLOT_TABLE_SIZE (16U)
14 #define NFS4_MAX_SLOT_TABLE (1024U)
15 #define NFS4_NO_SLOT ((u32)-1)
16 
17 #if IS_ENABLED(CONFIG_NFS_V4)
18 
19 /* Sessions slot seqid */
20 struct nfs4_slot {
21 	struct nfs4_slot_table	*table;
22 	struct nfs4_slot	*next;
23 	unsigned long		generation;
24 	u32			slot_nr;
25 	u32		 	seq_nr;
26 	u32		 	seq_nr_last_acked;
27 	u32		 	seq_nr_highest_sent;
28 	unsigned int		privileged : 1,
29 				seq_done : 1;
30 };
31 
32 /* Sessions */
33 enum nfs4_slot_tbl_state {
34 	NFS4_SLOT_TBL_DRAINING,
35 };
36 
37 #define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, BITS_PER_LONG)
38 struct nfs4_slot_table {
39 	struct nfs4_session *session;		/* Parent session */
40 	struct nfs4_slot *slots;		/* seqid per slot */
41 	unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
42 	spinlock_t	slot_tbl_lock;
43 	struct rpc_wait_queue	slot_tbl_waitq;	/* allocators may wait here */
44 	wait_queue_head_t	slot_waitq;	/* Completion wait on slot */
45 	u32		max_slots;		/* # slots in table */
46 	u32		max_slotid;		/* Max allowed slotid value */
47 	u32		highest_used_slotid;	/* sent to server on each SEQ.
48 						 * op for dynamic resizing */
49 	u32		target_highest_slotid;	/* Server max_slot target */
50 	u32		server_highest_slotid;	/* Server highest slotid */
51 	s32		d_target_highest_slotid; /* Derivative */
52 	s32		d2_target_highest_slotid; /* 2nd derivative */
53 	unsigned long	generation;		/* Generation counter for
54 						   target_highest_slotid */
55 	struct completion complete;
56 	unsigned long	slot_tbl_state;
57 };
58 
59 /*
60  * Session related parameters
61  */
62 struct nfs4_session {
63 	struct nfs4_sessionid		sess_id;
64 	u32				flags;
65 	unsigned long			session_state;
66 	u32				hash_alg;
67 	u32				ssv_len;
68 
69 	/* The fore and back channel */
70 	struct nfs4_channel_attrs	fc_attrs;
71 	struct nfs4_slot_table		fc_slot_table;
72 	struct nfs4_channel_attrs	bc_attrs;
73 	struct nfs4_slot_table		bc_slot_table;
74 	struct nfs_client		*clp;
75 };
76 
77 enum nfs4_session_state {
78 	NFS4_SESSION_INITING,
79 	NFS4_SESSION_ESTABLISHED,
80 };
81 
82 extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
83 		unsigned int max_reqs, const char *queue);
84 extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
85 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
86 extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
87 extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
88 		u32 slotid, u32 seq_nr,
89 		unsigned long timeout);
90 extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
91 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
92 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
93 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
94 		struct nfs4_slot *slot);
95 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
96 
97 static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
98 {
99 	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
100 }
101 
102 static inline bool nfs4_test_locked_slot(const struct nfs4_slot_table *tbl,
103 		u32 slotid)
104 {
105 	return !!test_bit(slotid, tbl->used_slots);
106 }
107 
108 static inline struct nfs4_session *nfs4_get_session(const struct nfs_client *clp)
109 {
110 	return clp->cl_session;
111 }
112 
113 #if defined(CONFIG_NFS_V4_1)
114 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
115 		u32 target_highest_slotid);
116 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
117 		struct nfs4_slot *slot,
118 		struct nfs4_sequence_res *res);
119 
120 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
121 
122 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
123 extern void nfs4_destroy_session(struct nfs4_session *session);
124 extern int nfs4_init_session(struct nfs_client *clp);
125 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
126 
127 /*
128  * Determine if sessions are in use.
129  */
130 static inline int nfs4_has_session(const struct nfs_client *clp)
131 {
132 	if (clp->cl_session)
133 		return 1;
134 	return 0;
135 }
136 
137 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
138 {
139 	if (nfs4_has_session(clp))
140 		return (clp->cl_session->flags & SESSION4_PERSIST);
141 	return 0;
142 }
143 
144 static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
145 		const struct nfs4_sessionid *src)
146 {
147 	memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
148 }
149 
150 #ifdef CONFIG_CRC32
151 /*
152  * nfs_session_id_hash - calculate the crc32 hash for the session id
153  * @session - pointer to session
154  */
155 #define nfs_session_id_hash(sess_id) \
156 	(~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
157 #else
158 #define nfs_session_id_hash(session) (0)
159 #endif
160 #else /* defined(CONFIG_NFS_V4_1) */
161 
162 static inline int nfs4_init_session(struct nfs_client *clp)
163 {
164 	return 0;
165 }
166 
167 /*
168  * Determine if sessions are in use.
169  */
170 static inline int nfs4_has_session(const struct nfs_client *clp)
171 {
172 	return 0;
173 }
174 
175 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
176 {
177 	return 0;
178 }
179 
180 #define nfs_session_id_hash(session) (0)
181 
182 #endif /* defined(CONFIG_NFS_V4_1) */
183 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
184 #endif /* __LINUX_FS_NFS_NFS4SESSION_H */
185